On 2021-09-21 09:22, Dmitry Baryshkov wrote:
The DSI host might be left in some state by the bootloader. If this
state generates an IRQ, it might hang the system by holding the
interrupt line before the driver sets up the DSI host to the known
state.
Move the request/free_irq calls into msm_dsi_host_power_on/_off calls,
so that we can be sure that the interrupt is delivered when the host is
in the known state.
Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
This is a valid change and we have seen interrupt storms in downstream happening
when like you said the bootloader leaves the DSI host in unknown state. Just one question below.
--- drivers/gpu/drm/msm/dsi/dsi_host.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index e269df285136..cd842347a6b1 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c@@ -1951,15 +1951,6 @@ int msm_dsi_host_modeset_init(struct mipi_dsi_host *host,return ret; } - ret = devm_request_irq(&pdev->dev, msm_host->irq, - dsi_host_irq, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, - "dsi_isr", msm_host); - if (ret < 0) { - DRM_DEV_ERROR(&pdev->dev, "failed to request IRQ%u: %d\n", - msm_host->irq, ret); - return ret; - } - msm_host->dev = dev; ret = cfg_hnd->ops->tx_buf_alloc(msm_host, SZ_4K); if (ret) {@@ -2413,6 +2404,16 @@ int msm_dsi_host_power_on(struct mipi_dsi_host *host,if (msm_host->disp_en_gpio) gpiod_set_value(msm_host->disp_en_gpio, 1); + ret = devm_request_irq(&msm_host->pdev->dev, msm_host->irq, + dsi_host_irq, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, + "dsi_isr", msm_host); + if (ret < 0) { + DRM_DEV_ERROR(&msm_host->pdev->dev, "failed to request IRQ%u: %d\n", + msm_host->irq, ret); + return ret; + } + +
Do you want to move this to msm_dsi_host_enable()? So without the controller being enabled it is still in unknown state?Also do you want to do this after dsi0 and dsi1 are initialized to account for
dual dsi cases?
msm_host->power_on = true; mutex_unlock(&msm_host->dev_mutex);@@ -2439,6 +2440,8 @@ int msm_dsi_host_power_off(struct mipi_dsi_host *host)goto unlock_ret; } + devm_free_irq(&msm_host->pdev->dev, msm_host->irq, msm_host); + dsi_ctrl_config(msm_host, false, NULL, NULL); if (msm_host->disp_en_gpio)
